Lawn mower having circular blades



April 18, 1950 E. E. LEE

LAWN MOWER HAVING CIRCULAR BLADES Filed Dec. '26, 1947 2 Sheets-Sheet l-Ear/ E. Lea

Patented Apr. 18, 1950 UNITED STATES ATENT FFHCE 3 Claims. l

My invention relates to improvements in lawn mowers of the type havingcircular rotary cutter blades.

A primary object of the invention is to provide a manually-operated lawnmower, adapted to cut grass of any height, and particularly well adaptedto cut tall tough grass.

A further object of the invention is to provide a lawn mower which islight and easy to push.

A still further object of the invention is to provide a lawn mower ofthe above mentioned class, which is simplified and practical in design,durable, and relatively inexpensive to manufacture.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are employed to designate like parts throughout thesame,

Figure 1 is a plan view of the lawn mower embodying the invention, thehandle being broken away, part in horizontal section.

Figure 2 is a transverse vertical section taken on line 22 of Figure 1.

Figure 3 is a bottom plan view of the invention taken on line 33 ofFigure 4.

Figure 4 is a central vertical longitudinal section taken on line i e ofFigure 1.

In the drawings, where for the purpose of the illustration is shown apreferred embodiment of the invention, the numeral Ill designates anupwardly and rearwardly inclined pivoted yoke, including a generallyhorizontal cross bar ll, having a lawn mower handle I2 rigidly securedthereto at the transverse center of the lawn mower. The yoke ill furtherincludes straight side 53, provided at their lower ends with laterallyoutwardly extending horizontal axles M, which are in axial alignment.

Each axle It carries a reduced outer extension it, integral therewith,and screw-threaded at its outer end it, to receive a nut ll.Ball-bearings it are mounted upon each reduced extension 15, inwardly ofthe nut ll. Ground-engaging drive wheels is are mounted upon the outerraces of ball-bearings it, as shown, and these wheels l9 includeinwardly disposed annular ring gears 26, integral therewith. The wheelsI9 are, of course, freely rotatable. Disposed adjacent to the inner sideof each wheel i3, and mounted upon the axles it, are non rotatablecircular discs 2 i, having central hubs 22, engaging over axles M, asshown. The discs 2i also include outer annular flanges 23, having theirouter edges disposed adjacent to the inner sides of wheels l9.

Formed upon each disc 2!, near its outer periphery is alaterally-projecting tubular boss 24, which receives one end of ahorizontal transverse rotatable shaft 25. The shaft 25 has its outerends journaled in ball-bearings 26. Rigidly secured to the outer ends ofshaft 25 for rotation therewith are pinions 2?, which mesh with ringgears 20, and. are driven thereby. Mounted upon the shaft 25, near itscenter portion for rotation with the same are a pair ofaxially-shiftable bevel gears 28 and 2 9. The gears 28 and 29 have axialkeyways 39, to slidably receive an elongated key 3|, secured to shaft25.

Disposed between the discs 2|, and close to the ground is a relativelythin flat pulley housing, designated generally by the numeral 32. Thispulley housing 32 comprises a top guard plate 33, which is fiat and thinand extends for substantially the full distance between discs 2!, andfrom a point adjacent to the rear edges of wheels l9 forwardly, asshown. Forwardly of the wheels IS, the guard plate flares laterallyoutwardly at both sides to form a pair of circularly curved forward endportions 34. The outer sides 35 of portions 34 are disposed laterallyoutwardly of the wheels l9, and the portions 34 are provided withforwardly-projecting pointed guide teeth or members 35', adapted tocontact the sides of curbing, tombstones, trees, and the like, and toguide the mower along the same, so that grass may be out very close tosuch objects. Inwardly of the guide teeth 55, the portions 54havecircumferentially spaced shearing teeth 36, to coact with rotarycutting elements, to be described, for cutting tough tall grass, and thelike. The teeth 36 of each portion 34 extend about the forwardcircularly curved ends of the portions and converge to the point betweenthe two portions 34, where a single tooth 3? may be formed.

Adjacent to the forward edges of wheels 19, the guard plate 33 has sideupstanding apertured, lugs 38 formed upon it. Rigid rearwardly inclinedbrackets 39 are rigidly secured at their lower ends to lugs 38, and attheir top ends to the inner sides of discs 25. The brackets serve topartially support the guard plate 33, and to hold the discs Z l againstrotation. Directly beneath the axles It, the guard plate has additionalside vertical lugs All, and these lugs as are rigidly secured to theinner sides of discs 2| and serve to support the rear portion of guardplate 33.

The pulley housing 32 further comprises a bottom plate M, which isgenerally fiat and horizontal, and spaced downwardly from guard plate 33to form a relatively narrow space between the two plates. The bottomplate 4| conforms generally to the shape of top guard plate 33, butterminates short of the forward end of guard plate 33, as shown dottedin Figure l. The forward end of bottom plate 4| has a contour which isparallel to the curved forward end of guard plate 33, as shown. At itsmarginal edges, bottom plate 4| has an upstanding vertical flange 42,which extends completely around both sides of plate 4|, and across therear end of the same. At its rear side, the flange 42 carries ahorizontal top flange 43, which extends completely across the rear endof plates 33 and 4|, and the flange 43 is rigidly secured to guard plate33 by screws 44, or the like. Near its forward edge, and at thetransverse center of the mower, the bottom plate 4! carries a dependingground-engaging swiveled roller or caster 45, serving to support theforward end of pulley housing 32, as the mower is pushed over theground.

Rotatably mounted upon the pulley housing 32, at the transverse centerof the mower, and disposed directly below shaft 25, is a short verticalshaft 45, suitably journaled in a ball-bearing 4?, or ball-bearings, andhaving rigidly secured to its top end a bevel gear 48, adapted to meshwith either of gears 28 or 29, to be driven thereby. The rotatable shaft46 carries a grooved pulley 49, secured to it for rotation therewith,and this pulley is disposed in the space between plates 33 and 4|, asshown. The shaft 46 is suitably held against axial movement with respectto pulley housing 32. Also mounted upon the pulley housing 32 andextending through plates 33 and M. and securely held against rotationand axial movement with respect to the housing, are short, verticalshafts 50, and 52. The shaft 55 is disposed at the transverse center ofthe mower, and spaced forwardly from shaft 46, as shown. The shafts 5|and 52 are disposed at the centers of circularly curved portions 34.Rotatably mounted upon the shafts 53, 5| and 52, and disposed betweenthe plates 33 and 4| are grooved pulleys 53, 54 and 55, each beingprovided with a ball-bearing 56, to insure the free rotation of thepulleys upon their shafts. A driving V-belt 51 engages about the pulleys49, 53, 54 and 55, as shown clearly in Figure 3. Longitudinallyextending slots 58 are provided in plates 33 and 4| for shaft 53, sothat pulley 53 may be adjusted to vary the tension of belt 51. Mountedupon each of the shafts 5| and 52, above the pulleys 54 and 55 are fiatcircular cutter blades 59 and 60. These blades are adapted to rotatewith shafts 5| and 52, and are disposed in close spaced relation to theunder side of guard plate portions 34, and concentric therewith.

The cutter blades 55 and 53 have cutting teeth 5|, which coact with thestationary teeth 35 of portions 34 to cut grass, and the like. Thediagonal inner edges 62 of guide teeth 35' serve to guide grass close toa curbing, or the like, into contact with the coacting teeth 35 and 5|.

Means are provided to reverse the direction of rotation of cutter blades59 and 65, so that the same may be removed and turned over, so that bothsides of the same may be utilized. Such means includes a laterallyadjustable plate 63 having longitudinal slots 64, to receive studs 55which are secured to plate 33. Wing nuts 56 are carried by studs 65, andserve to clamp plate 63 in the selected position. Rigidly secured toplate 63, by any suitable means are a pair of upstanding arms orbrackets 61 having transverse openings 68 which slidably receive thehubs 69 of gears 28 and 29 which rotate within the openings 68. As shownin Figure 1, with the plate 53 shifted to the right, the gear 28 mesheswith gear 48, to drive the cutter blades 59 and 60 in one direction.When the plate 63 is shifted to the left, the gear 28 is shifted out ofmesh with gear 48, and gear 29 enters into mesh with it, to drive thecutter blades in the opposite direction. The hubs 69 cannot move axiallyrelative to arms 51, but are freely rotatable in the openings 68, asstated.

In use, the device is operated like any manually operated mower, and iseasy to push through very tall tough grass. The mower is useful to cutgrass growing close to walls, curbing, sidewalks, and the like.

It is to be understood that the form of the invention herewith shown anddescribed, is to be taken as a preferred example of the same, and thatvarious changes in the shape, size and arrangement of parts may beresorted to, without departin from the spirit of the invention, or thescope of the sub-joined claims.

What claimed is:

l. A lawn mower, comprising a handle including transverse axleextensions, ground engaging wheels rotatably mounted upon the axleextension, non-rotatable upstanding discs mounted upon the axleextensions inwardly of the wheels and spaced from the wheels and havingopenings, a transverse shaft rotatably mounted within the openings ofthe discs and extending between the discs and wheels and having partswhich engage the wheels and rotated thereby, a thin flat casingincluding spaced top and bottom plates extending between the discs andsecured to the discs, the casing being disposed close to the ground andextending forwardly of the front edges of the wheels and laterallyoutwardly of the wheels upon both sides of the lawn mower, the forwardend of the casing being open, the casing being provided with teeth inthe forward edge of one of said plates, rotary cutters mounted betweenthe plates of the casing and forwardly of the wheels and having teeth tocoact with the teeth of the casing, a gear mounted upon the transverseshaft for rotation therewith, a second gear mounted upon the casingadjacent to the gear and meshing with the gear, the second gear having aspindle projecting between the plates of the casing, and drivingconnecting means lnountec between the plates of the casing andoperatively connecting the rotary cutters and spindle of the secondgear.

2. A lawn mower, comprising a handle including axle extensions, groundengaging wheels rotatably mounted upon the axle extensions, nonrotatableplates mounted upon the axle extensions inwardly of the wheels andhaving openings, a shaft rotatably mounted within the open ings andextending through the plates and having parts engaging the wheels androtated. thereby, a thin fiat casing including spaced top and bottomplates extending between the plates and secured to the discs andarranged close to the ground, the casing extending forwardly of thefront edges of the wheels and laterally outwardly of the wheels uponboth sides of the lawn mower, the forward end of the casing being open,the casing being provided with teeth in the forward edge of one of saidcasing plates, rotary substantially fiat cutters mounted between thecasing plates near the forward edges thereof and having teeth to coactwith the teeth of the casing, belt and pulley means mounted between thecasing plates and operatively connected with the cutters for rotatingthem, and gearing operatively connecting the shaft and belt and pulleymeans.

3. In a lawn mower, a non-rotatable axle, ground engaging Wheelsrotatably mounted. upon the axle near the opposite ends thereof, a thinflat casing including spaced top and bottom Slates mounted upon thenon-rotatable axle and disposed beneath the same and close to theground, the casing extending between the wheels and forwardly of thewheels for a substantial distance, the casing being laterally enlargedforwardly of the wheels so that the sides of the casing projectlaterally outwardly of the wheels, the forward end of the casing havingits forward edge provided with cutting teeth forming a relativelystationary cutting element extending for substantially the full distancebeween the sides of the casing adjacent to its open forward end,

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,132,465 Gast Oct. 11, 19382,134,115 Flammang Oct. 25, 1938 2,267,944 Osterholm Dec. 30, 1941

